I purchased this Pass B1 pre amp from an Audio Circle member, its based on the B1 board that Nelson sells, and the rest of it is his DIY build. Yes the chassis is basic and plain, this pre amp will win no beauty contests. However everything is functional, and it makes a great budget option.
Pass designs an active impedance buffering stage that matches impedance between source components and amplifiers, which is the main limitation of passive pre amps. The builder uses a linear power brick for the power supply to this circuit, and since its not in the signal path there is no effect on sound quality due to it. Good quality parts are used inside it, including Sonic Caps, which are not cheap.
Has two inputs, one set of outputs. Has a mute circuit. Switch positions are not marked, but I will give you the settings in the instructions, and you can mark them if you wish.
Sell for $250, which makes it a very affordable pre amp. Of course you do need to be sure your source component has enough output voltage to drive your amplifier. But if you do, then you get some of the most detailed and transparent sound possible!
